In order to increase a peak rate of data of radio resources in the CELL-FACH state and improve experience of UE, a enhanced CELL-FACH state is proposed in a manner that a High Speed Packet Access (HSPA) enhancement technology is introduced into the CELL-FACH state. Meanwhile, an enhanced CELL-PCH state is proposed in order to reduce delay for state transition between the CELL-FACH state and the CELL-PCH.
The UE, which is in the enhanced CELL-PCH state, monitors the paging indicator carried through the Paging Indicator Channel (PICH) by means of Discontinuous Reception (DRX), and receives information from High Speed Shared Control Channel (HS-SCCH) according to the mapping relationship between the paging indicator and HS-SCCH. If identifier information (e.g., HS-DSCH Radio Network Temporary Identifier (H-RNTI)) for the UE is detected on HS-SCCH, then the UE transits from CELL-PCH state to CELL-FACH state. After the state transition, the state transition information is notified to the radio network controller with a measurement report, and the radio network controller forwards the measurement report to a base station. The base station executes resource scheduling based on the received measurement report forwarded by the radio network controller. Then, the radio network controller maintains and updates the respective UE states according to the state transition information transmitted by the UE.
As the UE, which is provided with DRX mechanism and in the CELL-PCH state and the CELL-FACH state, receives data discontinuously in different DRX periods and the DRX period during which the UE is in the CELL-FACH state is much shorter than the period during which the UE is in the CELL-PCH state. After the state of the UE is transited, the radio network controller will receive the state transition information transmitted by the UE in a certain time period. During this time period, the UE state stored in the radio network controller is different from the actual state of the UE. Thereby the radio network controller would still transmit data to the UE in terms of the DRX period during which the UE is in the CELL-PCH state, whereas data will be lost due to the UE in the CELL-FACH state.